Effects of concurrent use of an ankle support with a laterally wedged insole for medial knee osteoarthritis.

Objective: To determine the biomechanical and symptomatic effects of concurrent use of an ankle support and a laterally wedged insole on adults with symptomatic medial compartment knee osteoarthritis.

Design: Randomized, crossover clinical trial.

Setting: Outpatient gait analysis laboratory.

Participants: Fourteen adults, mean age 51.9 +/- 8.3 years, with symptomatic medial compartment knee osteoarthritis and no previous lower-limb surgeries or history of wedged insole use were recruited through a radiology database and phone screen.

Interventions: Subjects were randomized to use a laterally wedged insole before (n = 8) or after (n = 6) use of the insole with an ankle support for 2 weeks.

Main Outcome Measures: Lower-limb alignment by radiographic hip-knee-ankle angle, talocalcaneal, and talar tilt angles; medial compartment loading by the external knee adduction moment; and pain by visual analog scale and the Knee Osteoarthritis Outcome Score pain subscale.

Results: There were no differences between groups for age, gender, body mass index, baseline knee pain, or alignment. Augmentation of the wedged insole with the ankle supporter did not result in any significant changes in lower-limb alignment or external knee adduction moment. Intergroup crossover comparisons demonstrated a 10.5-point greater average improvement in Knee Osteoarthritis Outcome Score pain subscale (P < .011) and a trend towards a 10.2-point improvement in the Activities of Daily Living subscale (P < .055) with the wedged insole alone in comparison with concurrent use of the ankle support with the wedged insole.

Conclusion: Concurrent use of an ankle support did not appear to improve the effects of a laterally wedged insole on lower-limb mechanical alignment or medial compartment loading. Improved pain and activities of daily living with use of the wedged insole alone suggests that use of an ankle support may attenuate clinical benefit.